CN116373604A - Pre-charging circuit, control method and device based on pre-charging circuit and vehicle - Google Patents

Pre-charging circuit, control method and device based on pre-charging circuit and vehicle Download PDF

Info

Publication number
CN116373604A
CN116373604A CN202310255098.4A CN202310255098A CN116373604A CN 116373604 A CN116373604 A CN 116373604A CN 202310255098 A CN202310255098 A CN 202310255098A CN 116373604 A CN116373604 A CN 116373604A
Authority
CN
China
Prior art keywords
precharge
switch
detection
relay
branch
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202310255098.4A
Other languages
Chinese (zh)
Inventor
周胜强
赵莹
张强
贾茹
张晓琛
曹斌
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Neusoft Reach Automotive Technology Shenyang Co Ltd
Original Assignee
Neusoft Reach Automotive Technology Shenyang Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Neusoft Reach Automotive Technology Shenyang Co Ltd filed Critical Neusoft Reach Automotive Technology Shenyang Co Ltd
Priority to CN202310255098.4A priority Critical patent/CN116373604A/en
Publication of CN116373604A publication Critical patent/CN116373604A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L3/00—Electric devices on electrically-propelled vehicles for safety purposes; Monitoring operating variables, e.g. speed, deceleration or energy consumption
    • B60L3/0023—Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L3/00—Electric devices on electrically-propelled vehicles for safety purposes; Monitoring operating variables, e.g. speed, deceleration or energy consumption
    • B60L3/0023—Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train
    • B60L3/0046—Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train relating to electric energy storage systems, e.g. batteries or capacitors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L58/00—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles
    • B60L58/10—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/70—Energy storage systems for electromobility, e.g. batteries

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Sustainable Energy (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Charge And Discharge Circuits For Batteries Or The Like (AREA)

Abstract

The application provides a precharge circuit, a control method, a device and a vehicle based on the precharge circuit, wherein the precharge circuit comprises: the first branch circuit is electrically connected with two ends of the power supply and comprises a first switch and a first load which are connected in series; the second branch is connected in parallel with the first branch and comprises a pre-charging unit, a second switch and a second load which are connected in series; and the first end of the third switch is electrically connected with the second end of the first switch, and the second end of the third switch is electrically connected with the first end of the second load. Through the precharge circuit of this application, can eliminate the influence of voltage acquisition precision to a certain extent, improve the accuracy of precharge proportion, receive great impact when the power is being inhaled to main positive relay in follow-up charging process reduction, improve main positive relay's life.

Description

Pre-charging circuit, control method and device based on pre-charging circuit and vehicle
Technical Field
The present application relates to the field of circuit technologies, and in particular, to a pre-charging circuit, a control method and device based on the pre-charging circuit, and a vehicle.
Background
Along with the development of clean energy, the number of electric vehicles is also increased, and the electric vehicles can comprise pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, fuel cell vehicles and the like. In the use process of the electric automobile, the control of high-voltage power-up, power-down and precharge is needed to be realized based on a precharge circuit. Specifically, the pre-charging circuit generally includes capacitors, when the vehicle starts, the main relay needs to be closed to supply power to the load of the vehicle, and because of the capacitors, if the main relay is directly closed, when the main relay is closed, the capacitors are equivalent to a short circuit, and a large impact current is generated at the moment of closing the main relay, and the impact current directly damages the main relay and even damages the power battery, so that the pre-charging is performed before the vehicle starts.
After detecting that the precharge ratio reaches the precharge ratio threshold, the precharge process is completed, and then high-voltage power-up is performed. Specifically, when the pre-charge ratio of the battery pack reaches the pre-charge ratio threshold, the pre-charge operation is generally terminated by powering up the relay. However, the inventor researches that in the practical application process, due to the influence of the sampling precision and the circuit structure, the pre-charge proportion obtained in practice may be low, so that the relay is subjected to larger impact during electrification and suction, and the service life of the relay is poor.
Disclosure of Invention
Some embodiments of the present application provide a pre-charge circuit, a control method, a device and a vehicle based on the pre-charge circuit, which can at least partially solve the above problems existing in the prior art.
According to one aspect of the present application, there is provided a precharge circuit, which may include: the first branch circuit is electrically connected with two ends of the power supply and comprises a first switch and a first load which are connected in series; the second branch is connected with the first branch in parallel and comprises a pre-charging unit, a second switch and a second load which are connected in series; and the first end of the third switch is electrically connected with the second end of the first switch, and the second end of the third switch is electrically connected with the first end of the second load.
In one embodiment of the present application, the precharge circuit may further include: and the third branch is connected with the second switch and the second load in parallel, and comprises a capacitor and a main negative relay.
In another aspect, the present application provides a control method based on a precharge circuit, where the precharge unit includes a precharge relay, a main positive relay, and a precharge resistor, and the method may include: performing relay adhesion detection on the pre-charge circuit, and testing a first detection point to obtain a first detection voltage, wherein the first detection point is a node where the first branch and the second branch meet; if the precharge circuit passes through the relay adhesion detection, precharging the precharge circuit, and testing a second detection point to obtain a third detection voltage, wherein the second detection point is a node where the third branch and the second branch meet; obtaining a precharge ratio based on the first detection voltage and the third detection voltage; and comparing the pre-charge ratio with the pre-charge ratio threshold interval, and if the pre-charge ratio is detected to be positioned in the pre-charge ratio threshold interval, completing pre-charge.
In one embodiment of the present application, performing relay adhesion detection on the precharge circuit may include: closing the first switch and the second switch, opening the third switch, and testing a second detection point to obtain a second detection voltage; and determining whether the main positive relay is stuck or not based on the first detection voltage and the second detection voltage.
In one embodiment of the present application, the pre-charging circuit is pre-charged, and the second detection point is tested to obtain a third detection voltage, which may include: and opening the first switch and the second switch, closing the third switch and the pre-charging relay, and testing the second detection point to obtain the third detection voltage.
In one embodiment of the present application, the pre-charge ratio is a ratio of the third detection voltage to the first detection voltage.
Still another aspect of the present application provides a control device based on a precharge circuit, where the precharge unit includes a precharge relay, a main positive relay, and a precharge resistor, and may include: the adhesion detection module is used for carrying out relay adhesion detection on the pre-charge circuit and testing a first detection point to obtain a first detection voltage, wherein the first detection point is a node where the first branch and the second branch meet; the precharge module is used for precharging the precharge circuit and testing a second detection point to obtain a third detection voltage, wherein the second detection point is a node where the third branch and the second branch meet; the control module is used for obtaining a pre-charge proportion based on the first detection voltage and the third detection voltage; and comparing the pre-charge ratio with the pre-charge ratio threshold interval, and if the pre-charge ratio is detected to be positioned in the pre-charge ratio threshold interval, completing pre-charge.
In one embodiment of the present application, the precharge module is configured to open the first switch and the second switch, close the third switch and the precharge relay, and test the second detection point to obtain the third detection voltage.
In one embodiment of the present application, the pre-charge ratio is a ratio of the third detection voltage to the first detection voltage.
Yet another aspect of the application provides a vehicle, which may include: the control device of the precharge circuit described above and the precharge circuit described above.
According to the embodiment of the application, through the pre-charging circuit, the influence of voltage acquisition precision can be eliminated to a certain extent, the precision of the pre-charging proportion is improved, the main positive relay is reduced in the subsequent charging process and is subjected to larger impact when being electrified, and the service life of the main positive relay is prolonged.
Drawings
Other features, objects and advantages of the present application will become more apparent upon reading the detailed description of non-limiting embodiments, made with reference to the following drawings. Wherein:
FIG. 1 is a schematic diagram of a precharge circuit 100 according to an embodiment of the present application;
fig. 2 is a flowchart of a control method 200 based on the precharge circuit 100 according to an embodiment of the present application;
FIG. 3 is a schematic illustration of a pre-charge scale curve according to an exemplary embodiment of the present application;
fig. 4 is a schematic diagram of a control device 400 based on the precharge circuit 100 according to an embodiment of the present application.
Detailed Description
For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed description are merely illustrative of exemplary embodiments of the application and are not intended to limit the scope of the application in any way. Like reference numerals refer to like elements throughout the specification. The expression "and/or" includes any and all combinations of one or more of the associated listed items.
In the drawings, the size, dimensions and shape of elements have been slightly adjusted for convenience of description. The figures are merely examples and are not drawn to scale. As used herein, the terms "about," "approximately," and the like are used as terms of a table approximation, not as terms of a table degree, and are intended to account for inherent deviations in measured or calculated values that will be recognized by one of ordinary skill in the art. In addition, in this application, the order in which the processes of the steps are described does not necessarily indicate the order in which the processes occur in actual practice, unless explicitly defined otherwise or the context may be inferred.
It will be further understood that terms such as "comprises," "comprising," "includes," "including," "having," "containing," "includes" and/or "including" are open-ended, rather than closed-ended, terms that specify the presence of the stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof. Furthermore, when a statement such as "at least one of the following" appears after a list of features listed, it modifies the entire list of features rather than just modifying the individual elements in the list. Furthermore, when describing embodiments of the present application, use of "may" means "one or more embodiments of the present application. Also, the term "exemplary" is intended to refer to an example or illustration.
Unless otherwise defined, all terms (including engineering and technical terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
In addition, embodiments and features of embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.
In a related embodiment, the battery management system (battery management system, BMS for short) detects the pre-charge ratio of the battery in a voltage sampling manner, and when the pre-charge ratio reaches a pre-charge ratio threshold, the main positive relay is controlled to absorb power, but because the sampling voltage is affected by the load parameter in the pre-charge circuit, the accuracy of the pre-charge ratio is further affected, a larger deviation between the actual pre-charge ratio and the standard pre-charge ratio may occur, and then the main positive relay is subjected to a larger impact when absorbing power, so that the service life of the main positive relay is affected. However, the voltage sampling may be affected by the electric components such as the resistor, the capacitor, the control unit, and the characteristics of the precharge circuit, and the set threshold of the precharge ratio is usually a constant value, so in practical application, there is a great problem in controlling the relay according to the set threshold.
Fig. 1 is a schematic diagram of a precharge circuit 100 according to an embodiment of the present application. As shown in fig. 1, the precharge circuit 100 may include a power supply 110, a first leg 120, a second leg 130, a third leg 140, and a third switch 150.
In the exemplary embodiment of the present application, the first branch 120 is electrically connected to two ends of the power supply 110, and may include a first switch 121 and a first load 122, where the first switch 121 and the first load 122 are connected in series, and the first switch 121 may be a field effect transistor (MOS) or a switch, for controlling a circuit state of the first branch 120, and the first load 122 may be at least one voltage divider device. The first switch 121 is a field effect transistor MOS1, and the first branch 120 includes two voltage dividing devices, which are a resistor R1 and a resistor R2, respectively.
In the exemplary embodiment of the present application, the second branch 130 is connected in parallel with the first branch 120, and the second branch 130 may include a pre-charging unit 131, a second switch 132, and a second load 133, wherein the pre-charging unit 131, the second switch 132, and the second load 133 are electrically connected in series in order. The pre-charging unit 131 may include a pre-charging relay 131-1, a main positive relay 131-2, and a pre-charging resistor 131-3, the pre-charging relay 131-1 and the pre-charging resistor 131-3 are connected in series and then connected in parallel with the main positive relay 131-2, a capacitor in a circuit may be charged through the pre-charging relay 131-1 and the pre-charging resistor 131-3, and the main positive relay 131-2 may be used to perform high voltage charging after the battery is pre-charged. The second switch 132 may be a field effect transistor (MOS) or a switch for controlling a circuit state of the second branch 130, and the second load 133 may be at least one voltage divider device. The second switch is illustratively a field effect transistor MOS2, and the second branch 130 includes two voltage dividing devices, a resistor R3 and a resistor R4, respectively.
In an exemplary embodiment of the present application, the pre-charging resistor may be a plurality of resistors (not shown in the drawings), where the plurality of resistors may form an array of m×n, and M, N is a positive integer. And the resistances of the resistors in the array may be the same or different. The pre-charging resistor uses the resistor array, even if one resistor in the array fails, other resistors in the array can protect the pre-charging circuit, so that the impact of current generated by the short circuit of the pre-charging resistor on the relay can be avoided to a certain extent, and the service life of the relay is prolonged.
In an exemplary embodiment of the present application, the precharge circuit 100 may further include a third branch 140, the third branch 140 being connected in parallel with the second switch 132 and the second load 133 in the second branch, the third branch 140 may include a capacitor 141 and a main negative relay 142, wherein the capacitor 141 and the main negative relay 142 are connected in series.
In this exemplary embodiment of the present application, the precharge circuit 100 may further include a third switch 150, where a first end of the third switch 150 is connected to a second end of the first switch 121, a second end of the third switch 150 is electrically connected to a first end of the second load 133, the third switch 150 may be a field effect transistor (MOS) or a switch, and the precharge circuit 100 may collect the voltage at the first detection point 1 and the voltage at the second detection point 2 by controlling the state of the third switch 150, so that the accuracy of the voltage at the first detection point 1 and the voltage at the second detection point 2 is only affected by the first load, which is beneficial to further eliminating the sampling error, improving the accuracy of the precharge ratio, and improving the service life of the relay to a certain extent.
Fig. 2 is a flowchart of a control method 200 based on the precharge circuit 100 according to an embodiment of the present application. As shown in fig. 2, the control method 200 of the precharge circuit may include:
step S210: performing relay adhesion detection on the precharge circuit, and testing a first detection point to obtain a first detection voltage, wherein the first detection point is a node where the first branch and the second branch meet;
step S220: if the precharge path passes through relay adhesion detection, precharging the precharge path, and testing a second detection point to obtain a third detection voltage, wherein the second detection point is a node where the third branch and the second branch meet;
step S230: obtaining a precharge ratio based on the first detection voltage and the third detection voltage;
step S240: and comparing the pre-charge ratio with a pre-charge ratio threshold interval, and if the pre-charge ratio is detected to be positioned in the pre-charge ratio threshold interval, completing pre-charge.
The details of the steps of the control method 200 of the precharge circuit described above will be described in detail below with reference to fig. 1.
In an exemplary embodiment of the present application, performing relay adhesion detection on the precharge circuit may include: closing the first switch MOS1 and the second switch MOS2, opening the third switch MOS3, and testing the first detection point and the second detection point to obtain a first detection voltage U1 and a second detection voltage U2, where the first detection point is a node (e.g., point 1 in fig. 1) where the first branch 120 and the second branch 130 meet, and the second detection point is a node (e.g., point 2 in fig. 1) where the third branch 140 and the second branch 130 meet. If the values of the first detection voltage U1 and the second detection voltage U2 are equal or the difference between the first detection voltage U1 and the second detection voltage U2 is smaller than the voltage detection threshold, it may be determined that the main positive relay 131-2 is stuck, and the subsequent precharge process needs to be stopped. If the difference between the first detection voltage U1 and the second detection voltage U2 is greater than or equal to the voltage detection threshold, it may be determined that the adhesion does not occur in the main positive relay 131-2. It may then be further determined whether adhesion has occurred to the main negative relay 142, and if adhesion has not occurred to both the main positive relay 131-2 and the main negative relay 142, adhesion detection is completed. Through carrying out adhesion test to the circuit, can guarantee that main positive relay and main negative relay are intact, avoid because the damage of relay influences the security of precharge circuit.
In an exemplary embodiment of the present application, a control command may be issued by the vehicle controller to a Battery Management System (BMS) that controls the opening and closing of electrical components based on the control command, wherein the electrical components may include a main positive relay 131-2, a main negative relay 142, a pre-charge relay 131-1, a first switch 121, a second switch 132, and a third switch 150.
In an exemplary embodiment of the present application, after the precharge circuit passes the relay blocking detection, the precharge circuit is precharged, and the second detection point is tested, to obtain the third detection voltage. Illustratively, the first switch 121 and the second switch 132 are opened, the third switch 150 and the precharge relay 131-1 are closed, and the second detection point is tested to obtain the third detection voltage U3. For the precharge circuit, the accuracy of the third detection voltage U3 is affected only by the first load 122 (i.e., the resistor R1 and the resistor R2).
In the exemplary embodiment of the present application, after the third detection voltage is obtained, the precharge ratio may also be obtained based on the first detection voltage and the third detection voltage, where the precharge ratio is a ratio of the third detection voltage to the first detection voltage. The influence of voltage acquisition precision can be eliminated to a certain extent through calculating the pre-charge proportion between the third detection voltage and the first detection voltage, namely, the voltage acquisition precision of the third detection voltage and the first detection voltage is only influenced by the first load, the influence factors are the same, the precision of the pre-charge proportion is improved, the impact of the main positive relay on the power-on is reduced in the subsequent charging process, and the service life of the main positive relay is prolonged.
In the exemplary embodiment of the present application, the precharge ratio may be compared with a precharge ratio threshold interval, and if the precharge ratio is located in the precharge ratio threshold interval, the precharge is completed. Fig. 3 is a schematic illustration of a pre-charge scale curve according to an exemplary embodiment of the present application. As shown in fig. 3, the horizontal axis may represent the precharge time, and the vertical axis may represent the precharge ratio. In order to ensure the safety of the subsequent power-up process, it is therefore necessary to set an upper limit of the precharge proportion and a lower limit of the precharge proportion, wherein a threshold interval of the precharge proportion is between the upper limit of the precharge proportion and the lower limit of the precharge proportion. Illustratively, the upper limit K of the priming proportion Upper part ＝U2*(1+x 2 )/U1*(1-x 1 ) Upper limit K of precharge proportion Lower part(s) ＝U2*(1-x 2 )/U1*(1+x 1 ) Wherein x is 1 For the voltage sampling precision of the first detection point, x 2 For the voltage sampling accuracy of the second detection point, the voltage sampling accuracy of the first detection point and the voltage sampling accuracy of the second detection point are correlated with the chip controlling the sampling thereof. For example, the lower limit of the precharge ratio may be set to 94%, and the upper limit of the precharge ratio may be set to 98%, and when the precharge ratio is detected to be in the range of 94% to 98%, it indicates that the precharge is completed. The lower and upper limits of the pre-charge ratio of the present application are exemplary illustrations, and those skilled in the art will appreciate that the pre-charge ratio may be based on actual vehicle cleaningThe lower limit of the pre-charge proportion and the upper limit of the pre-charge proportion are set, and the application is not limited.
In an exemplary embodiment of the present application, after the precharge process is completed, the main positive relay is turned on, the precharge relay is turned off, and high-voltage power-up is performed. When a Battery Management System (BMS) detects an extreme protection condition trigger, such as overcharge, overdischarge, over-temperature, overcurrent short circuit and the like, the battery management system enters a high-voltage power down flow, and the main positive relay is disconnected first, and then the main negative relay is disconnected.
The present application also provides a control device 400 based on the precharge circuit 100, and fig. 4 is a schematic diagram of the control device 400 based on the precharge circuit 100 according to an embodiment of the present application. As shown in fig. 4, the control device 400 of the precharge circuit may include a blocking detection module 410, a precharge module 420, and a control module 430.
In an exemplary embodiment of the present application, the adhesion detection module 410 may be configured to perform relay adhesion detection on the precharge circuit, and test a first detection point to obtain a first detection voltage, where the first detection point is a node where the first branch meets the second branch. Illustratively, relay stick detection of the precharge circuit may include: closing the first switch MOS1 and the second switch MOS2, opening the third switch MOS3, and testing the first detection point and the second detection point to obtain a first detection voltage U1 and a second detection voltage U2, where the first detection point is a node (e.g., point 1 in fig. 1) where the first branch 120 and the second branch 130 meet, and the second detection point is a node (e.g., point 2 in fig. 1) where the third branch 140 and the second branch 130 meet. If the values of the first detection voltage U1 and the second detection voltage U2 are equal or the difference between the first detection voltage U1 and the second detection voltage U2 is smaller than the voltage detection threshold, it may be determined that the main positive relay 131-2 is stuck, and the subsequent precharge process needs to be stopped. If the difference between the first detection voltage U1 and the second detection voltage U2 is greater than or equal to the voltage detection threshold, it may be determined that the adhesion does not occur in the main positive relay 131-2. Then, whether the main negative relay is stuck or not can be further judged, and if the main positive relay and the main negative relay 142 are not stuck, the sticking detection is completed. By performing an adhesion test on the circuit, the primary positive relay 131-2 and the primary negative relay 142 can be ensured to be intact, and the safety of the pre-charging circuit is prevented from being influenced by the damage of the relays.
In an exemplary embodiment of the present application, a control command may be issued by the vehicle controller to a Battery Management System (BMS) that controls the opening and closing of electrical components based on the control command, wherein the electrical components may include a main positive relay 131-2, a main negative relay 142, a pre-charge relay 131-1, a first switch 121, a second switch 132, and a third switch 150.
In an exemplary embodiment of the present application, the precharge module 420 may be configured to precharge the precharge circuit and test the second detection point to obtain the third detection voltage, where the second detection point is a node where the third branch meets the second branch. Illustratively, the precharge circuit is precharged after the precharge circuit passes the relay stick detection. Specifically, the first switch 121 and the second switch 132 are opened, the third switch 150 and the precharge relay 131-1 are closed, and the second detection point is tested to obtain the third detection voltage U3. For the precharge circuit, the accuracy of the third detection voltage U3 is affected only by the first load 122 (i.e., the resistor R1 and the resistor R2).
In an exemplary embodiment of the present application, the control module 330 may be configured to obtain the pre-charge ratio based on the first detection voltage and the third detection voltage, where the pre-charge ratio is a ratio of the third detection voltage to the first detection voltage. The influence of voltage acquisition precision can be eliminated to a certain extent through calculating the pre-charge proportion between the third detection voltage and the first detection voltage, namely, the voltage acquisition precision of the third detection voltage and the first detection voltage is only influenced by the first load, the influence factors are the same, the precision of the pre-charge proportion is improved, the impact of the main positive relay on the power-on is reduced in the subsequent charging process, and the service life of the main positive relay is prolonged.
In an exemplary embodiment of the present application, the control module 430 may be further configured to compare the precharge ratio with a precharge ratio threshold interval, and complete the precharge if the precharge ratio is located in the precharge ratio threshold interval.In connection with fig. 3, in order to ensure the safety of the subsequent power-up process, it is therefore necessary to set an upper limit of the precharge proportion and a lower limit of the precharge proportion, wherein the upper limit of the precharge proportion and the lower limit of the precharge proportion are within a threshold interval of the precharge proportion. Illustratively, the upper limit K of the priming proportion Upper part ＝U2*(1+x 2 )/U1*(1-x 1 ) Upper limit K of precharge proportion Lower part(s) ＝U2*(1-x 2 )/U1*(1+x 1 ) Wherein x is 1 For the voltage sampling precision of the first detection point, x 2 For the voltage sampling accuracy of the second detection point, the voltage sampling accuracy of the first detection point and the voltage sampling accuracy of the second detection point are correlated with the chip controlling the sampling thereof. For example, the lower limit of the precharge ratio may be set to 94%, and the upper limit of the precharge ratio may be set to 98%, and when the precharge ratio is detected to be in the range of 94% to 98%, it indicates that the precharge is completed. The lower and upper limits of the pre-charge ratio of the present application are exemplary illustrations, and those skilled in the art will recognize that the lower and upper limits of the pre-charge ratio may be set based on actual cleaning of the vehicle, and the present application is not limited thereto.
In an exemplary embodiment of the present application, the control module 430 may also control the relay to perform a power-up process and a power-down process after the precharge process is completed. Illustratively, after the precharge is completed, the main positive relay is energized, the precharge relay is opened, and a high voltage is applied. When a Battery Management System (BMS) detects an extreme protection condition trigger, such as overcharge, overdischarge, over-temperature, overcurrent short circuit and the like, the battery management system enters a high-voltage power down flow, and the main positive relay is disconnected first, and then the main negative relay is disconnected.
The present application also provides a vehicle, which may include the above-described precharge circuit or a control device of the precharge circuit, and may perform the above-described control method of the precharge circuit.
The purpose, technical scheme and beneficial effects of the invention are further described in detail in the detailed description. It is to be understood that the above description is only of specific embodiments of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A precharge circuit, comprising:
the first branch circuit is electrically connected with two ends of the power supply and comprises a first switch and a first load which are connected in series;
the second branch is connected with the first branch in parallel and comprises a pre-charging unit, a second switch and a second load which are connected in series;
and the first end of the third switch is electrically connected with the second end of the first switch, and the second end of the third switch is electrically connected with the first end of the second load.
2. The precharge circuit of claim 1, wherein said precharge circuit further comprises: and the third branch is connected with the second switch and the second load in parallel, and comprises a capacitor and a main negative relay.
3. A control method based on the precharge circuit of claim 2, the precharge unit including a precharge relay, a main positive relay, and a precharge resistor, comprising:
performing relay adhesion detection on the pre-charge circuit, and testing a first detection point to obtain a first detection voltage, wherein the first detection point is a node where the first branch and the second branch meet;
if the precharge circuit passes through the relay adhesion detection, precharging the precharge circuit, and testing a second detection point to obtain a third detection voltage, wherein the second detection point is a node where the third branch and the second branch meet;
obtaining a precharge ratio based on the first detection voltage and the third detection voltage;
and comparing the pre-charge ratio with the pre-charge ratio threshold interval, and if the pre-charge ratio is detected to be positioned in the pre-charge ratio threshold interval, completing pre-charge.
4. A control method of a precharge circuit according to claim 3, wherein performing relay adhesion detection on the precharge circuit comprises:
closing the first switch and the second switch, opening the third switch, and testing a second detection point to obtain a second detection voltage;
and determining whether the main positive relay is stuck or not based on the first detection voltage and the second detection voltage.
5. A control method of a precharge circuit according to claim 3, wherein precharging the precharge circuit and testing the second detection point to obtain the third detection voltage comprises:
and opening the first switch and the second switch, closing the third switch and the pre-charging relay, and testing the second detection point to obtain the third detection voltage.
6. The method according to claim 5, wherein the precharge ratio is a ratio of the third detection voltage to the first detection voltage.
7. A control device based on the precharge circuit of claim 2, the precharge unit including a precharge relay, a main positive relay, and a precharge resistor, comprising:
the adhesion detection module is used for carrying out relay adhesion detection on the pre-charge circuit and testing a first detection point to obtain a first detection voltage, wherein the first detection point is a node where the first branch and the second branch meet;
the precharge module is used for precharging the precharge circuit and testing a second detection point to obtain a third detection voltage, wherein the second detection point is a node where the third branch and the second branch meet;
the control module is used for obtaining a pre-charge proportion based on the first detection voltage and the third detection voltage; and comparing the pre-charge ratio with the pre-charge ratio threshold interval, and if the pre-charge ratio is detected to be positioned in the pre-charge ratio threshold interval, completing pre-charge.
8. The control device of the precharge circuit according to claim 7, wherein the precharge module is configured to open the first switch and the second switch, close the third switch and the precharge relay, and test the second detection point to obtain the third detection voltage.
9. The control device for a precharge circuit according to claim 7, wherein the precharge ratio is a ratio of the third detection voltage to the first detection voltage.
10. A vehicle, characterized by comprising: a control device of a precharge circuit according to any one of claims 7 to 9 and a precharge circuit according to claim 2.
CN202310255098.4A 2023-03-15 2023-03-15 Pre-charging circuit, control method and device based on pre-charging circuit and vehicle Pending CN116373604A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310255098.4A CN116373604A (en) 2023-03-15 2023-03-15 Pre-charging circuit, control method and device based on pre-charging circuit and vehicle

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310255098.4A CN116373604A (en) 2023-03-15 2023-03-15 Pre-charging circuit, control method and device based on pre-charging circuit and vehicle

Publications (1)

Publication Number Publication Date
CN116373604A true CN116373604A (en) 2023-07-04

Family

ID=86962572

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310255098.4A Pending CN116373604A (en) 2023-03-15 2023-03-15 Pre-charging circuit, control method and device based on pre-charging circuit and vehicle

Country Status (1)

Country Link
CN (1) CN116373604A (en)

Similar Documents

Publication Publication Date Title
CN108832683B (en) Control method and control device for high-voltage electrification and automobile
EP3518374B1 (en) Power supply system
CN107238758B (en) New energy automobile high-voltage system Y capacitance detection system and method and new energy automobile
KR102044737B1 (en) Relay control system and control method
CN102511009B (en) Method for diagnosing the operation of a device for cutting off and connecting a battery from/to the onboard power network of a motor vehicle
US8362784B2 (en) Capacitor capacitance diagnosis device and electric power apparatus equipped with capacitor capacitance diagnosis device
CN101162793B (en) High voltage energy storage connection monitoring system and method
CN101453043A (en) Secondary battery charging method and device
CN107478908B (en) Electric vehicle insulation detection device and detection method thereof
US6404170B2 (en) Electrical storage capacitor system having initializing function
JP6623193B2 (en) Method and apparatus for charging a vehicle battery
KR101795319B1 (en) System and method for detecting opening of fuse in high voltage system of vehicle
KR102437323B1 (en) Apparatus for diagnosing battery pack
CN116373604A (en) Pre-charging circuit, control method and device based on pre-charging circuit and vehicle
CN205901352U (en) Supply assembly
EP3872506A1 (en) Battery control device
CN110988770A (en) High-voltage pre-charging simulation device for electric automobile and simulation method for pre-charging process
CN113022312B (en) High-voltage power-on control method, high-voltage power-on circuit and electric vehicle
CN111137150A (en) Charging control method and vehicle-mounted charger
EP0668963A1 (en) Fault diagnosis method for injectors of internal combustion engine high-pressure injection systems
US11498425B2 (en) Ground fault detection device
CN117124853A (en) Pre-charging circuit, control method and device based on pre-charging circuit and vehicle
KR101647693B1 (en) Apparatus and method for detecting wire disconnection using pull-down circuit in battery management system
CN114981121A (en) Welding prevention method and battery system using the same
CN110745015A (en) Pre-charging loop protection control system and method and automobile

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination